This invention relates to slides for slide valves such as those used in hydraulic control systems and to methods for manufacturing such slides.
In hydraulic transmissions, for example, hydraulic control systems having slide valves are used and, in some cases, several slides must be arranged in one valve housing to achieve a high functional compactness.
In conventional slide valve arrangements, the slides are generally made of aluminum, and they require at least one turning and two grinding operations. Between the two grinding operations, surface hardening or anodization processes must be performed. In order to achieve adequate stability of the valve control edges when subjected to high flow velocity of the hydraulic fluid with the consequent danger of cavitation, the anodization must provide a suitable wear-resistant and hard surface coating, which requires control of current intensity, time and bath temperature among other factors. Manufacture of such slides thus involves a great deal of expense.